Method of making elastic yarn



Nov. 25, 1941. F. D, CHITTENDE N 2,263,612

METHOD OF MAKING ELASTIC YARN v Filed Nov. 13, 1940 2 Sheets-Sheet l INVENTOR. .Fyelie fl Okiilendem ATTORNEY Nov. 25, 1941. I F. D. CHITTENDEN 2,263,612"

, METHOD OF MAKING ELASTIC YARN Filed Novf 15, 1940 2 Sheets-Sheet 2 Q INVENTOR. Walk 2. aizzzzemzen f M3..W

ATTORNEY by said patent.

Patented Nov. 25', 1941 METHOD OF MAKING ELASTIC YARN Fayette D. Chittenden, Rumtord, R. 1., asslgnor to United States Rubber Company, New York, ,N. Y., a corporation or New .Yersey Application November is, 1940, Serial No. 365,460

*2 Claims.

This invention relates to an improved method of making a balanced elastic yarn comprising a rubber core having a textile yarn wrapped helically about the core as a cover. a

It has been proposed heretofore to make a balanced single cover elasticyarn on a core covering machine by feeding a twisted rubber thread through the hollow spindle which supports and revolves the package of textile yarn about the thread, to thereby wrap this yarn about the rubber thread in a direction opposite to that of the twist previously'imparted to the thread to produce a balanced elastic yarn. Such a construction is described by the Foster Patent No..

2,024,155, Elastic yarn, and the elastic yarn contemplated by this Foster patent is of great commercial importance because it is cheaper to produce than the conventional double covered type of elastic yarn, and for many uses is equally satisfactory'.

The present invention contemplates a novel method wherebya balanced single cover elastic yarn similar to that disclosed by the Foster patent may be made on standard textile twisting equipment instead of the more expensive conventional core covering equipment contemplated The use oi textile twisting equipment to manufacture elastic yarn, as herein contemplated, will reduce the cost of such elastic yarn because textile twisting equipment provided with a solid rotating spindle is cheaper to build andoperate than the hollow spindle equipment contemplated by said Foster patent,

and is readily available whereas the conventional type of rubber covering equipment employing a hollow spindle is expensive to build and operate,

and is less readily available on the market hecause its use is confined largely to the covering of rubber thread.

There are a number or types of textile twisters in general use which are capable of being employed as herein contemplated to wrap a textile yarn about a pre-twisted rubber core as a cover. These twisters all twist the rubber thread as they 1 wrap the-cover about the same and may be divided into two general classes as follows:

(1) Up stroke twisters such as commonly used I for twisting silk and rayon, in which the yarn is advanced axially in an upward direction from a revolving spool containing the supply of yarn. These twisters usually employ a flyer at the upperv end of the spool; and

(2) Down stroke twisters such used for twisting cotton and wool in which the yarn to be twisted is red in a downward direction as commonly from a source of supply to a revolving spindle provided with a ring and traveler.

elastic yarn may be produced in accordance with the present invention on an up stroke twister and also one. down stroke twister.

In the drawings:

Fig. 1 is a conventional diagrammatic view or one form of up stroke twister employed to twist the rubber core preparatory to forming the balanced elastic yarn.

Fig. 2 is a conventional diagrammatic view or an up stroke twister as employed to twist the rubber. core and yarn together so as to form the desired elastic yarn, following the operation of Fig. 1.

Fig. 3 is a view similar to Fig. 1 showing two ends of covering yarn being laid along side the twisted rubber thread in place of the single end of covering yarn of Fig. 1.

Fig. 4 is a conventional diagrammatic view of a down stroke twister employed to twist the pretwisted rubber core and textile yarn together to form the desired elastic yarn.

Fig. Sis a side view on an enlarged scale oran elastic yarn produced on the apparatus of Figs. 1 and 2 or upon the apparatus of Fig. 4; and

Fig. 6 is a similar view of an elastic yam having two ends of covering yarn, such as may be produced by employing the apparatus of Figs. 2 and 3.

Various forms of apparatus'may be employed to carry out the method of the present invention provided it is capable of performing the steps 0). (1) pre-twisting the bare rubber thread, (2) bringing the pre-twlst rubber thread and textile yarn together and (3) twisting them together to wrap the yarn about the core as a cover. The steps of bringing the pie-twisted rubber thread and textile yarn together in position to be twisted one about the other may be performed in two separate and distinct operations as is done by employing the up twister equipment of Figs. 1

a and 2, or it may be done in one continuous op- When the apparatus of F18. fl is used it willbe necessary to pre-twist the bare rubber thread by any suitable mechanism such for example as that shown in Fig. 1 provided the covering yarn is omitted from the apparatus of Fig. 1 so that the twisted rubber core alone will be wound upon the take-up spool.

Now turning to a moredetailed description of the drawings and starting with Figs. 1 and 3, there is shown in these figures an up stroke twister provided with a let-off spool I0. Upon this spool is wound an untwisted rubber-thread II formed of natural or artificial rubber or other rubber like material having the desired strength, elasticity, durability and other required properties. The spool III is mounted upon a spindle I2 to be rotated rapidly thereby and this spindle may be driven by any suitable means such as the pulley I3 and belt I4. The spindle I2 is rotatably supported by any suitable means such as the bracket I5.

Above the rotating spool I is provided a pigtail IS in axial alignment with the spindle I2 and adapted to guide the rubber thread I I as it is unwound from the spool I0 and passes upwardly therefrom. It is contemplated that the spool I 0 will be rotated at high speed say 10,000 R. P. M. or higher and therefore the rubber thread may balloon considerably, but the size of this balloon may be controlled to a considerable degree by varying the distance of the pigtail I6 from the upper end of the spool I0.

It is highly desirable to provide feed means for the rubber thread I I adapted to pull the thread from the spool I0 at a definite speed relative to the R. P..M. of the spindle I2 to thereby control the number of twists that are imparted per inch to the thread II. This may be accomplished by providing the power driven feed rolls II arranged to have the rubber thread passed therebetween. The twisted rubber thread II upon leaving these feed rolls passes upwardly in the construction shown to a take-up spool I8 which may be driven at the desired speed irrespective of the amount of material wound thereupon by causing this spool to rest upon a power driven roll I9. The swinging arms pivotally supported at 2I serve to support the spool I8 so that it may rest by gravity on the driving roll I9. As the twisted rubber thread II approaches the take-up spool I8 it is wound evenly thereupon by the traverse mechanism 22 which is shown as having an upwardly extending arm that carries a thread guide or roller 23.

The apparatus of Fig. 1 s rves not only to twist the rubber thread II andwind it upon the take-up spool I8 but also to perform a doubling operation in which it lays the cover forming yarn 24 alongside of the rubber thread H to be wound therewith upon the spool I8. plished in the construction shown by providing a supply of the covering yarn 24 such as the cone 25 from which the yarn may be pulled of! endwise as shown. It is then subjected to the desired tension by passing through the tension device 26 which may consist .of a fixed lower disc and a floating upper disc that rests by. gravity upon the yarn. Thelyarn 24 then passes through a pigtail 21 carried by the traverse rod 22, and passes upwardly from the pigtail to the guide 23 alongside of the twisted rubber thread II. In this manner the twisted thread II and covering mm 24 are wound side by side upon the take-up spool I8 under the desired tension, the tension of the rubber thread and covering yarn being independ- This is accom-v ently controlled by the tension mechanism I7 and 26 respectively.

This completes the first series of steps when the apparatus of Figs. 1 and 2 is employed. Should it be desired to provide a rubber core with two ends of covering yarn instead of a single end as shown by the construction of Fig. 1, then the construction of Fig. 3 may be employed wherein one end of yarn 24 is supplied by the cone 25 and a second end 24' is supplied by the cone 25'.

After the rubber thread II has been twisted and wound upon the take-up spool I8 with one or more ends of covering yarn, then this spool I8 may be transferred to the apparatus of Fig. 2

where it is mounted upon a rotating spindle 21' is provided pivotally mounted at 32 upon the upper end of the spindle 21. The flyer 3| may have oppositely extending arms as shown each of which has a thread guide so that one may guide the rubber core II and the other the yarn 24 as they are unwound from thespool I8. The thread and yarn then pass through a pigtail guide 33 at which point they are twisted together by the rotation of the spool I8. The thread II and yarn 24 are preferably drawn axially at the desired rate of speed from the rotating spool I8 by the power driven rolls 34. The elastic yarn 35 produced by the twisting apparatus just described upon leaving the feed rolls 34 may be wound onto a take-up spool 36 and is guided thereupon by the traverse mechanism 31. The spool 36 is preferably driven by a roll 38 similar to the roll I9 of Fig. 1.

In carrying out the method of the present invention it is contemplated that a relatively high twist will be imparted to the rubber core II by the apparatus of Fig. 1, as part of this twist will be removed by the apparatus of Fig. 2 when the rubber thread and covering yarn are twisted together. The spindle I2 should be rotated in the opposite direction to that of the spindle 2'! so that the apparatus of Fig. 2 will serve to remove a substantial p rtion, say half of the twist that was imparted to the rubber thread I I by the apparatus of Fig. '1. This will serve to produce a single cover elastic yarn such as shown in Fig. 5 in which the twist of the rubber core in one direction serves tobalance the helical wrappings of the cover in the opposite direction.

The down stroke twister of Fig. 4 may be employed in accordance with the present invention to produce in a continuous operation thedesired elastic yarn by bringing a. pre-twisted rubber core and the covering yarn together in side by side relation as they approach spinning or twisting mechanism, and then twisting the core and erably operated at a higher surface speed than the spool 40 to thereby stretch the rubber thread 39 the desired amount. The cover forming yam 43 may be supplied by the cone 44 and this yarn may be tensioned as desired as it leaves the cone by passing it through' the tension device 45 whereupon it passes about suitable guides and is delivered to the nip oi the feed rolls 42 in contacting relation with the rubber thread 39.

As the pre-twisted rubber thread 39 and covering yarn 43 leave. the feed rolls 42 they are twisted together to form the desired elastic yarn by any suitable means capable of performing a yarn plying operation such for example as twisting mechanisms employing the well known ring and traveler. As shown in Fig.4 the combined rubber thread and yarn pass from the feed rolls 42 to the pigtail 46 supported in axial alignment with the spinning spindle 41 which may be driven by the usual belt and whirl- The elastic yarn 48 formed of the rubber core 39. and covering yarn 43 passes through the traveler 49 mounted upon the ring 50 and is then wound into a package upon the spinning spindle 41.

The rubber core 39 is preferably kept under suilicient tension during the twisting operation to cause it to take a straight line position at the center of the elastic yarn when the latter is relieved from tension and this, as above pointed out causes the covering yarn-to form helical coils about the rubber core. The direction of rotation of the spindle 41 should be opposite to the twist previously put in the bare rubber core. That is the operation of twisting the core and cover together to produce the desired elastic yarn removes a substantial portion of the twist previously put in the bare rubber core, to thereby produce a balanced elastic yarn.

The elastic yarn shown in Fig. having a single end of yarn 24 wound helically about the pretwisted rubbercore II is such as may be pro duced on the apparatus of Figs; 1 and 2, or. upon the apparatus of Fig. 4., The elastic yarn of Fig. 6 having two ends of yarn 24 and 24' helically wrapped about the pre-twisted rubber core ll may be produced by employing first the apparatus of Fig. 3 and then the apparatus of Fig. 2. The elastic yarn shown in Figs. 5 and 6 is in the relaxed or unstretched condition.

Practically any type of textile yarn such as cotton, wool, silk, rayon, Nylon or the like and dyed to any desired color may be employed to cover the rubber core, and various core sizes may be used. The following examples are given as showing several of the many elastic yarns that have been produced by the present method.

Elastic yarn constructed byfthe present method I may have excellent strength imparted thereto by the single end of covering yarn, and the range 01' stretch may bevaried as desired from approximately' 100% to 300%. This variation in stretch f is secured largely by increasing or decreasing the' stretch of the rubber core as it is delivered to the twisting point, and by increasing or. decreasing the speed of the feed rolls, such as 42, relative to the spinning spindle speed to. thereby vary the amount of twist that is imparted to the core and cover.

Having thus described my invention, what I claim and desire to protect by Letters Patent is:

'1. The method of making elastic yarn which comprises, winding a twisted rubber thread and textile yarn upon a spool undercontrolled tension, then withdrawing the rubber thread and textile yarn endwise from said spool while this spool is rotated in'an opposite direction to the twist of said thread and at a sufiiciently high speed to remove a number of twists from each coil of the threadunwound from this spool, to thereby partly untwist said thread and twist the yarn and thread together by a yarn plying operationso that as the thread assumes a central position the yarn will lie helically about the rubber thread as a cover.

2. The method of making elastic yarn on an up twister which comprises, winding a twisted rubber thread and textile yarn upon a spool under independently controlled tensions, then rotating said spool in a direction to remove part of the twist from said thread and drawing the thread and yarn endwise in an upward direction from r this rotating spool at a definite rate relative to the speed of spool rotation so as to remove a numyarn which comprises, winding a twisted rubber thread and textile yarn side by side upon a spool,

ber of twists from each coil of the thread unwound from the spool to thereby partly untwist said thread and twist the yarn and thread together by a yarn plying operation so that as the thread assumes a central position the yarn will lie helically about the rubber thread as a cover.

3. The method of making a balanced single cover elastic yarn which comprises, winding a twisted rubber thread and textile yarn side by side upon a spool, then withdrawing the thread and yarn endwise from said spool while the latter is rotated in a direction to remove part or the twist of said rubber thread and at a speed to remove a number of twists from, each coil of the thread unwound from this spool, to thereby partly untwist said thread and twist the yarn and thread together by a yarn plying operation so that as the thread assumes a central position the yarn will lie helically about the thread as a cover so as to balance the opposite twist of the rubber thread and hold the rubber stretched.

4. The method of making a single cover elastic then withdrawing the rubber thread and textile yarn endwise from this spool but from the opposite sides thereof while the spool is being rotated in a direction to remove part of the twist 01' said thread, to thereby partly untwist said thread and twist the yarn and thread together by a yarn plying operation so that as the thread assumes a central position the yarn will lie helically about the rubber thread as a cover.

5. The method of making elastic yarn which comprises, winding a twisted rubber thread and a plurality of ends'of textile yarn upon a spool under controlled tension, then withdrawing the thread and ends of yarn endwise from said spool while this spool is rotated in an opposite direction to the twist of said thread and at a sufficiently high speed to remove a number of twists from each coil of the threadunwound from this spool,

to thereby partly untwist said thread and twist 6. The method of making a balanced single cover elastic yarn having a yarn cover which consists in advancing a pre-twisted rubber thread and a covering yarn under independently controlled tensions to a meeting point to thereby cover elastic yarn having a yarn cover on a down stroke twister which consists in advancing a pretwisted rubber thread and a covering yarn under independently controlled tensions to a meeting point to thereby bring the twisted rubber thread and covering yarn into side by side longitudinal relation, and then twisting them together by a yarn plying operation in a direction to remove part of the twist previously imparted to the rubber thread and place one about the other so that as the thread assumes a central position the yarn will lie helically about the rubber thread as a cover adapted to balance the opposite twist of the rubber thread.

FAYETTE D. CHITTENDEN. 

